DOPI

DOPI is a defense used after interference over ace-asking slam bidding conventions such as Blackwood and Roman Keycard Blackwood. It uses the Double and Pass bids as responses to enable you to answer partner’s query even when bidding space is restricted.

DOPI stands for “Double = 0, Pass =1” and serves as a good reminder of how you should bid after interference over 4NT ace-asking bid. This convention is often used alongside ROPI, which uses similar bids to communicate after opponents double the 4NT bid.

How to Use DOPI

After an opponent overcalls over Blackwood, you can use DOPI to make the following responses:

This same system can be used if Roman Key Card Blackwood is interrupted. Here are the responses for 3014 RKCB:

Response

Meaning

Double

0 or 3 keycards

Pass

1 or 4 keycards

Cheapest Bid

2 key cards without the Q of trumps

Second-Cheapest Bid

2 key cards with the Q of trumps

As you’d expect, the responses are switched round for 1430 RKCB:

Response

Meaning

Double

1 or 4 keycards

Pass

0 or 3 keycards

Cheapest Bid

2 key cards without the Q of trumps

Second-Cheapest Bid

2 key cards with the Q of trumps

Opponent Doubled? Try ROPI

ROPI, “Redouble = 0, Pass = 1”, is used in those situations where the opponent’s double your 4NT ace-ask instead of overcalling it.

The responses are pretty self-explanatory so we’ll only repeat them for Blackwood – you can probably figure out the RKCB equivalent:

Response

Meaning

Redouble

0 aces

Pass

1 ace

Cheapest Bid

2 aces

Second-Cheapest Bid

3 aces

Third-Cheapest Bid

4 aces

The One Small Problem With DOPI You Should Know About

When the opponent’s intervene above the 5th level of your suit DOPI you start to run out of bidding space. Consider the following auction:

1♠ – (3♥) – 4NT – (6♥) – ?

Using DOPI, two of the responses push you past 6♠. Even if the opponent’s intervene at the 5th level, if their suit is ranked higher than yours you have precious little bidding room.

The solution is DEPO (or its cousin, DOPE), which we’ll look at in the next section.

DEPO & DOPE

DEPO stands for “Double = Even, Pass = Odd” and is a simpler alternative to DOPI. The benefit of using it is that it is much simpler and doesn’t use any bidding space, so it can be used even when opponent’s bid too high for DOPI.

The responses are simple:

Response

Meaning

Double

Even number of aces (or keycards)

Pass

Odd number of aces (or keycards)

DOPE, or “Double = Odd, Pass = Even”, swaps these responses round:

Response

Meaning

Double

Odd number of aces (or keycards)

Pass

Even number of aces (or keycards)

Of course, you do lose the ability to communicate so much information. For this reason, some partnerships play both DOPI and DOPE, with an agreement that DOPI is standard but they use DOPE if the opponent’s bid above a pre-determined level. This works well as long as the partnership both remember which one they are playing!